(Proposal ID) S17B-078

(PI) Kawai, Nobuyuki

(Proposal Title)
Subaru Observations of Gamma-Ray Burst Afterglows

(Abstract)
We propose to conduct rapid "Target of Opportunity" observations of gamma-ray 
burst (GRB) afterglows using the prompt alerts from the Swift, INTEGRAL, Fermi
satellites and MAXI to pursue following goals:  (1) Detect and characterize 
optical afterglow of short GRBs to study their connection with gravitational 
wave sources, (2) Detect and identify GRBs in the re-ionization era (6<z<20)
(3) Examine the GRB-supernova  connection using low-z GRBs  (4) Probe the GRB 
environments and intergalactic medium through spectroscopy  (5) Study GRBs with
GeV gamma-ray emission  Larger sample of short GRBs afterglow will be searched 
using HSC. Afterglow spectroscopy would be used to check their origin in 
neutrons star binary merger, the prospected gravitational wave events. 
The afterglow of long GRBs provide a unique probe for the re-ionization of 
the Universe and the environment of GRB sources in star-forming galaxies. 
GRBs with GeV emission detected by Fermi are useful for understand the 
production mechanism of GRBs.